by Xiaohui Zhou, Zanxian Xia, Qin Lan, Julie Wang, Wenru Su, Yuan-Ping Han, Huimin Fan, Zhongmin Liu, William Stohl, Song Guo Zheng
BAFF, in addition to promoting B cell survival and differentiation, may affect T cells. The objective of this study was to determine the effect of BAFF on Th17 cell generation and its ramifications for the Th17 cell-driven disease, EAE. Methodology/Principal Findings
Th17 cells were increased in BAFF-Tg B6 (B6.BTg) mice and decreased in B6.Baff-/- mice. Th17 cells in B6.Baff-/- mice bearing a BAFF Tg (B6.Baff-/-.BTg mice) were identical to those in B6.BTg mice, indicating that membrane BAFF is dispensable for Th17 cell generation as long as soluble BAFF is plentiful. In T + non-T cell criss-cross co-cultures, Th17 cell generation was greatest in cultures containing B6.BTg T cells and lowest in cultures containing B6.Baff-/- T cells, regardless of the source of non-T cells. In cultures containing only T cells, Th17 cell generation followed an identical pattern. CD4+ cell expression of CD126 (IL-6R a chain) was increased in B6.BTg mice and decreased in B6.Baff-/- mice, and activation of STAT3 following stimulation with IL-6 + TGF-ß was also greatest in B6.BTg cells and lowest in B6.Baff-/- cells. EAE was clinically and pathologically most severe in B6.BTg mice and least severe in B6.Baff-/- mice and correlated with MOG35–55 peptide-induced Th17 cell responses. Conclusions/Significance
Collectively, these findings document a contribution of BAFF to pathogenic Th17 cell responses and suggest that BAFF antagonism may be efficacious in Th17 cell-driven diseases.